Op is probably past the point of caring now but .... I want to try for my own sake -
Witcher 3 is a great game that should be played if you like some or all of the following things - RPGs, Action, Graphics, Characters, Story, World design, high fantasy (more conan then DnD), crafting , adventuring, open world.
This game really tries to have it all ! an early trailer for it is what sold me on it , made me think it was like a medieval Grand Theft Auto and at times because of the high production value and polish for many of the main story quests it really does feel as well made as something like GTAV. This game is an RPG though , so you spend as much time reading and exploring as you do fighting. The combat system is often called the weakest link in Witcher 3 and although I'm trying to sell the whole thing for you OP , I can't really fully defend this one area. I think it's serviceable but I kept the difficulty on "normal" which means I wasn't really challenged by an encounter after the halfway mark. It's a combat system that feels like Dark Souls mixed with the ability wheels present in something like mass effect (although you don't have guns in witcher). When it all works properly it can feel like a visceral gory slaughter house , when the combat system falters, it can be frustrating. BUT to keep selling the game , I'll say that no matter how annoyed I would occasionally get (it wasn't that often at all) at the dodgy combat that the story/world/characters would pull me back in at a moments notice. This is the first time I've played an open world-ish RPG that I've not only finished but very much loved to sit and play. Bethesdas games by comparison have piss poor art direction, no real story and a sea of boring uninteresting characters. I have no investment in their worlds and so I never feel attached to anything , no reason to keep playing them. Witcher I wanted to keep going to see what town might be over the next hill or passed the next stream because I knew each town would have a story to look into , a quest filled with some level of heart break for some random towns person, a monster to kill.
I guess to sum it all up , Witcher 3 was one of the most immersive experiences I've ever had while playing a videogame. If you value being part of a huge living world within a game but want more direction (and better combat frankly) than a Bethesda game (eldar scrolls/fallout) then go ahead and give Witcher 3 a whirl.
Also , here is a link to the trailer that got me to buy the game last year at launch -
Witcher 3 Wild Hunt 5 minute gameplay demo
And for the record my experience with the series/books prior to this entry was pretty small. I knew they existed and I do own 1/2 but after 3 tries with 1 I haven't made it out of the first real area (it's a PC RPG with janky mouse based combat and it's built on biowares neverwinter nights engine). All I did with witcher 2 was load it up on a couple of occasions to see how pretty it looked but I intended to finish 1 before 2. Even with 3 I had plans to play it later , after completing 1 and 2 but I got hooked by 3 so quickly that I just kept playing.